The present invention relates to the accessing of cellular networks via local networks which are not native to the cellular system, and more particularly but not exclusively to providing users of a cellular system with the ability to access the enhanced services of a LAN or the like where available.
Interfacing between a cellular and a LAN system is problematic due to lack of compatibility of network types. Thus, for example cellular networks have security arrangements such as the SIM, which are simply not recognized by the LAN. If a cellular telephone attempts to connect to the cellular network via a LAN, it can only succeed in doing so if the cellular network is satisfied with its SIM credentials. Yet the LAN may not recognize parts of the SIM handshake as signals that need to be passed on, or may not pass them on correctly.
A further problem arises in that the LAN may allow connection to itself of terminal types that could not in themselves connect to the cellular network. If it is desired that such devices have the same access to the cellular networks then the LAN has to solve within itself all of the compatibility issues that arise.
The problem is how to provide services to users who are often cellular subscribers connecting via a. LAN and who may require services originating with the specific LAN to which they are connecting, Internet connectivity or access to cellular services. The problem may be broken up into two elements,
1) authentication of genuine cellular equipment via the LAN so that the cellular equipment can use the added advantages provided by the LAN, and
2) if and how to allow non-cellular devices compatible with the LAN, with access to services provided by or accessible via the LAN. In short, is it possible to allow cellular carriers to offer their subscribers access to Internet and other remote services, within or outside the cellular network, from local networks such as BlueTooth or 802.11b Wireless LAN, collectively designated as “Hot Spots”, where the users accessing the local network are in possession of terminals with the interfacing means to access the Hot Spots?
It is desirable to support any terminals that are capable of connecting to the local network, such as laptops, PDAs, etc., without requiring them to have direct access to the cellular network. Neither is it desirable to require such devices to have cellular network compatible equipment (e.g. SIM card), as a condition for the Hot Spot access.
Attempting to provide cellular access from non-cellular access networks raises security issues and related design principles. Successful overcoming of such issues raises the potential of a system architecture that enables expansion of services provided by Cellular Mobile Operators into various type of local access gateways, e.g. Wireless LAN (WLAN) Hot Spots, Wireless local loop, broad band routers etc. The demand in the market is currently to support scenarios where most local wireless access networks are based on WLAN Hot Spots, and thus many of the specific examples herein are directed at such scenarios. Nevertheless, the problems discussed herein apply to scenarios where broadband modems are used for local access, or any other type of local access networks. The local access networks include those that may be deployed by the Cellular Mobile Operator itself, Public local access networks operated by some Internet Service Providers, e.g. public Hot Spots operated by Wireless Service Provides (WISPs), corporate networks or even Private local access networks. The problem is how to support wide and fast integrated deployment of the new services while strictly retaining and even improving on the security standards and data protection required by and characteristic of the cellular network.
The fast deployment of Public Wireless LAN (WLAN) Hot Spots, with its present small subscriber base, becomes both an opportunity and a challenge for Cellular Mobile Operators. The challenge is that new Wireless Internet Service Providers (WISPs) may eventually compete with the Mobile Operators in providing wireless services to the same customers. The opportunity is the increase in services Cellular Mobile Operators provide to their subscribers, by leveraging on their existing large subscriber base to obtain favorable roaming agreements with these WISPs and expand cellular services into WLAN Hot Spots.
The wireless access infrastructure and the number of Wireless Internet Service Providers (WISPs) are growing rapidly. The users are able to access network services from both Public WLANs (located in airports, coffee shops, hospitals, etc.) and Private WLANs (located in for example in corporate campuses).
The Cellular Mobile Operators today possess an efficient and almost entirely secure billing architecture that supports roaming, that is connecting through other networks, as long as the other networks are compatible cellular networks. Extension of the advanced cellular accounting and roaming mechanisms, to support various types of local access, such as WLAN access, and also to provide value added services in Hot Spots is tempting but not trivial due to the incompatibility with cellular networks described above. Mobile Operators may for example wish to grant their customers secure and non-secure access from WLANs to their own services and be able to charge their cellular accounts. Likewise the WLAN operators would like to enable cellular customers to be able to access their LANs for the services on offer and be able to charge a cellular account. Enabling users to roam between WISPs, access various types of services, benefit from a high security level and be charged by their Cellular Mobile Operator in a single bill is a significant challenge to the Mobile Operator.
Services accessed through the Hot Spot may be located in a public network such as the Internet, in a private network or a shared network (e.g. the Mobile Operator's network, or a corporate network). Examples are browsing, location-based services, virtual private network (VPN) access, email, MMS, etc.
There is thus a widely recognized need for, and it would be highly advantageous to have, an interfacing system for LAN to cellular WAN which operates seamlessly from the point of view of the user, and allows identification and charging of the user through the security of the cellular system.